An overview of current intraoral 3D-camera systems is found in Int J Comput Dent 2013; 16: 143-162. The cameras described there use an endoscope-type design with a camera body and an access shaft into the mouth, which has an optical window or projectors and sensors at its end. For serial recordings, these cameras are guided freehanded and floating or supported over the row of teeth. According to experience, these known scanners are suited for the measurement of partial rows of teeth.
Application problems exist with scanners of this type when acquiring data from poorly visible surface parts, e.g. for interdental to mesial or distal-oriented natural tooth surfaces as well as for fine-detailed, partly vertical geometrical preparation surfaces. This applies also for the measurement of surfaces situated in the interdental spaces below the tooth equator because the possible jaw and mouth opening limits the alignment of the camera's viewing direction with its rigid endoscope shaft in particular in the region of the molar. Thereby, a complete measurement of the poorly visible surfaces of the rows of teeth is impeded by the manual alignment of the required viewing angles with the conventional construction of these cameras.
Particularly difficult is the acquisition of interdental buccal and lingual lateral surfaces, because it requires freehanded roll- and tilt-movements of the camera simultaneously with a floating movement along the rows of teeth. In addition, the camera needs to be moved within the range of depth of focus. Simultaneously, the soft parts of the cheeks and tongue need to be kept out of the measurement area and the salivation needs to be controlled.
For the mentioned reasons, a complete measurement of the rows of teeth of the complete dentition including the fully or partially toothed upper and lower jaws and a measurement of the palatine as well as of edentulous jaws is particularly complex with the known systems. The complete measurement of the dentition is important for the manufacturing of prosthetic reconstructions and prostheses as well as in orthodontics for the planning and the monitoring of the therapy. Therefore, the user should be enabled to execute the measurements as easily and quickly as possible. It is thereby desired that the measuring system of the camera is designed in such a way that it is adaptable during scanning of the rows of teeth to the varying anatomic topology of the jaws at complete, partial or fully edentulous dentition, and that the measurement is executed from different solid angles fully automatically by itself and thereby freeing the user from manually tuning the difficult solid-angle-adjustments of the camera needed to get a complete measurement.